Nishiura T, Fujii S, Kanayama Y, Nishikawa A, Tomiyama Y, Iida M, Karasuno T, Nakao H, Yonezawa T, Taniguchi N
Second Department of Internal Medicine, Osaka University Medical School, Japan.
Cancer Res. 1990 Sep 1;50(17):5345-50.
The carbohydrate structures and the enzymatic basis for glycosylation of IgG by bone marrow plasma cells were determined in 7 patients with monoclonal gammopathy of undetermined significance and 22 patients with IgG MM. Lectin-binding analysis showed that in all cases of monoclonal gammopathy of undetermined significance and normal controls the IgG heavy chains bound to Ricinus communis agglutinin more strongly than to concanavalin A. In contrast, the IgG in 11 of the 17 advanced cases of MM (stages II and III) studied reacted to concanavalin A more strongly. Structural analysis showed that the reduced R. communis agglutinin binding capacity of these MM IgGs was due to hypogalactosylation of IgG. The galactosyltransferase and N-acetylglucosaminyltransferase III activities of the bone marrow myeloma cells from 5 MM cases were found to have a low enzyme activity ratio of galactosyltransferase to N-acetylglucosaminyltransferase III which reflects the hypogalactosylation. This indicates that the difference in the carbohydrate moieties observed in myeloma proteins is due to variations in the activities of the two glycosyltransferases.
在7例意义未明的单克隆丙种球蛋白病患者和22例IgG型多发性骨髓瘤（MM）患者中，确定了骨髓浆细胞对IgG进行糖基化修饰的碳水化合物结构及酶学基础。凝集素结合分析显示，在所有意义未明的单克隆丙种球蛋白病病例及正常对照中，IgG重链与蓖麻凝集素的结合比与伴刀豆球蛋白A的结合更强。相反，在研究的17例晚期MM（II期和III期）病例中的11例中，IgG与伴刀豆球蛋白A的反应更强。结构分析表明，这些MM型IgG的蓖麻凝集素结合能力降低是由于IgG的半乳糖基化不足。发现5例MM患者的骨髓骨髓瘤细胞的半乳糖基转移酶和N - 乙酰葡糖胺基转移酶III活性具有较低的半乳糖基转移酶与N - 乙酰葡糖胺基转移酶III酶活性比，这反映了半乳糖基化不足。这表明在骨髓瘤蛋白中观察到的碳水化合物部分的差异是由于两种糖基转移酶活性的变化所致。
